Im trying to add a try catch that tells the user they cant plug in negative numbers

Question

I was able to add a try catch that tells the user that they cant use letters.However for some reason adding a try catch for negative numbers dosent seem to work.I know that

Answer 1

In order for your catch block to catch exception, the Exception needs to be thrown from the code. In case of negative numbers the line input= stdin.nextInt(); will not throw exception as it is perfectly legal for integer to be negative. You will need to add if condition like this:

input = stdin.nextInt();
if ( input < 0 ) {
  throw new Exception("Negative number entered");
}

But some consider this to be bad practice because you are using exceptions to control the flow of a program. So I give you another example how you can do this without throwing an exception:

input = stdin.nextInt();
if ( input < 0 ) {
  System.out.println("Only Positive Numbers Please");
  continue;  // will continue from the beginning of a loop
}